Computer swap on Mars Rover

"Don't flip out: I just flipped over to my B-side computer while the team looks into an A-side memory issue," says a message from the Mars rover Curiosity on its NASA Facebook page.

NASA's Luke Dubord to speak at DW 2013.

In response to a flash memory issue on the Mars rover Curiosity, NASA's ground team switched the rover to a redundant computer on Thursday, Feb. 28. The rover, with two computers called the A side and B side, is operating on the B-side while the team troubleshoots A-side. As of Saturday, Curiosity was out of safe mode and on Sunday was again able to use its high-gain antenna.

"We are making good progress in the recovery," said Mars Science
Laboratory Project Manager Richard Cook, of NASA's Jet Propulsion
Laboratory in a mission status report posted today. "One path of progress is evaluating the A-side with intent
to recover it as a backup. Also, we need to go through a series of steps
with the B-side, such as informing the computer about the state of the
rover -- the position of the arm, the position of the mast, that kind of
information."

NASA is still working on identifying the cause of the glitch.

According to a press release from NASA, the A-side computer may have some corrupted memory. The spacecraft remained in communications at all scheduled communication windows on Wednesday, but it did not send recorded data, only current status information. The status information revealed that the computer had not switched to the usual daily "sleep" mode when planned. Diagnostic work in a testing simulation at JPL indicates the situation involved corrupted memory at an A-side memory location used for addressing memory files.

Curiosity operated on the B-side during part of its flight to Mars and switched to the A-side before landing on the planet. The planned switch into safe mode occurred on Feb. 28

"We switched computers to get to a standard state from which to begin restoring routine operations," said Richard Cook of NASA's Jet Propulsion Laboratory, project manager for the Mars Science Laboratory Project, which built and operates Curiosity.

"While we are resuming operations on the B-side, we are also working to determine the best way to restore the A-side as a viable backup," said JPL engineer Magdy Bareh, leader of the mission's anomaly resolution team.